The present invention relates to fuel injection pumps for internal combustion engines, and in particular to a fuel injection pump which has a cam drive which simultaneously rotates and reciprocates a pump piston and has a stationary part and a part rotatably driven by a drive shaft.
Fuel injection pumps of the above-mentioned general type are known in the art. One such fuel injection pump is disclosed for example in the German patent document GM 90 14 068. The fuel injection pump disclosed in this reference has a pump piston which is rotatable and reciprocatingly movable by a cam drive and which limits a pump working chamber. The cam drive includes a stationary part which is formed as a roller ring and a part which is rotatable by a drive shaft and formed as a cam disk. The rotary position of the stationary part is fixed by a fixing element which engages in the stationary part, is supported in a sliding piece and forms as a pin. The sliding piece is guided in a pump housing tangentially to the stationary part with a small gap, so that the rotary position of the stationary part is fixed with a small gap. The fuel injection pump further has an electrically controlled valve which is operative for loading the pump working chamber during the pumping stroke of the pump piston for controlling the injection-active pump piston stroke. The time point of the closing of the valve is also controlled for controlling the injection start in dependence upon the operational parameters of the internal combustion engine. The fuel injection pump has the disadvantage that the sliding piece and the pin during their mounting are not visible, so that their mounting is difficult. Moreover, the machining of the receptacle for the sliding piece is difficult since it is arranged in a location in the pump housing which is not easily accessible. The pin is secured in the stationary part additionally by a rod, so that three structural parts are required for fixing the rotary position of the stationary part. Also, two fits, namely between the pin and the stationary part and between the sliding piece and its receptacle are provided, and they must be produced with high accuracy. It is to be understood that it is desirable to eliminate these disadvantages in the sense of an efficient manufacture and simple mounting.